Cartridge for light-weighted projectiles

ABSTRACT

A cartridge that can fire a light-weighted projectile, producing a pressure curve of the propellant gases similar to the pressure curve generated by the shot of a heavy weighted lead-core projectile. The cartridge propels the light-weighted projectile together with a capsule, which contains an inert load of high density metal powder. The capsule is divided in multiple parts, which disassemble when it leaves the firearm muzzle, spreading the metal powder in the air. The metal powder increases the mass which is accelerated by the propellant gases, keeping the pressure curve high enough to cycle a self-loading firearm mechanism. The metal powder consists of very thin particles which spreads and decelerates rapidly in the air, causing a controllable level of danger to personnel.

BACKGROUND OF THE INVENTION

The present invention relates to cartridges designed to propel light-weighted projectiles. This kind of cartridge is widely used for combat simulation and training When said light-weighted projectile is a capsule filled with paint, the cartridge is named marker. Marker cartridges can be used to simulate combat situations with real firearms between infantry or police trainees.

The main problem related to such cartridges is the fact that firearms are designed to operate with heavy lead-core projectiles. When the standard projectile is replaced by a light-weighted one, the internal ballistics is deeply affected and the pressure of the propellant gases falls to very low levels. If the firearm is self-loading, it means automatic or semi-automatic, the propellant gases will not generate enough energy to cycle the firearm mechanism when firing a light-weighted projectile.

To overcome this problem, the solutions given by the prior art use two approaches: modifying the cartridge and modifying the firearm.

U.S. Pat. No. 5,359,937 describes a reduced energy cartridge which propels a sub-caliber projectile using a sabot that travels only for a limited length inside the cartridge case. The special geometry of the cartridge case restraints the movement of the sabot. This invention requires the firearm to be modified, using a barrel which is different from the firearm's original one.

U.S. Pat. No. 5,700,972 describes a cartridge with a case which contains an internal chamber filled with compressed gas. The cartridge has no propellant. The compressed gas supplies the energy that propels the projectile and applies a force to the breech block to initiate the reloading cycle.

U.S. Pat. No. 7,225,741 B2 describes a two-stage reusable cartridge that uses propellant and a telescopic piston system to initiate the reloading cycle of the firearm. The cartridge requires a modified firearm to be fired appropriately.

The main advantage of the present invention in relation to the prior art is the possibility of using the cartridge in a non-modified standard firearm.

BRIEF SUMMARY OF THE INVENTION

The present invention is a firearm cartridge which propels a light-weighted projectile together with a collapsing capsule and an inert load of high density metal powder.

When a self-loading firearm, it means, automatic or semi-automatic firearm, is fired, part of the energy of the propellant gases is used to accelerate the projectile and other part is used to cycle the firearm mechanism. The cycle of the mechanism has basically two steps:

-   -   a) the fired cartridge case is taken out of the chamber and         ejected;     -   b) a new ammunition is loaded in the chamber.

The firearms are designed to cycle with the pressure of the propellant gases created by a common cartridge. A common cartridge uses a lead-core projectile. If the pressure of the shot is, for any reason, smaller than the designed pressure, the cycle will not happen and a new cartridge will not be loaded in the chamber. There are two main factors that define the pressure curve of a shot:

-   -   a) the propellant charge (which includes the kind of propellant         and the amount of it);     -   b) the projectile's mass.

Both factors work together. Generally, it's not possible to reach an appropriate pressure if one of these factors is not correctly set up. It means that, if the projectile's mass is not large enough, the firearm will not cycle; and doesn't matter the amount of propellant which is being burnt.

Lead is one of the heaviest materials available. Its relative density is 11.3 comparing with pure water. The engineering plastics have relative densities around 1. Aluminum has relative density of 2.7. A 9×19 mm Full Metal Jacket lead-core bullet, weights approximately 8 g. The same projectile made of aluminum would weight 1.9 g, and, if made of plastic, it would weight only 0.7 g. The 9×19 mm pistols and submachine guns are designed to operate with projectiles that weights around 8 g. Projectiles with less than 2 g wouldn't raise the propellant gases pressure to the level which the firearm cycles, when fired by a standard cartridge.

A marker projectile with plastic or aluminum structure containing an ink payload is an example of a projectile which hasn't enough mass to raise the pressure of the propellant gases to cycle the firearm. This kind of projectile is used for training and simulations. Other example of projectile which can't cycle the firearm's mechanism, when fired by a standard cartridge, is a less-lethal rubber bullet.

The present invention is intended to overcome the problem of firing a light-weighted projectile with an automatic or semi-automatic firearm. The cartridge fires a light-weighted projectile together with an inert load of metal powder. The weight of that load is approximately the same of a common lead-core bullet.

The load of metal powder is packed together with the projectile inside a collapsing capsule. The collapsing capsule has the same external shape of an ordinary bullet. When the cartridge is fired, the capsule, which contains the inert load of metal powder, and the projectile are accelerated by the gases, creating a pressure curve high enough to cycle the firearm.

When the capsule leaves the muzzle, it disassembles, allowing the inert load of metal powder to spread in the air and the projectile to fly to the target. The metal powder decelerates rapidly and offers a tolerable level of danger to people. The capsule parts are flat, light-weighted and are not lethal. In FIG. 2, it is shown the capsule disassembling right after it leaves the firearm muzzle.

The present invention can also be used as a blank cartridge. If the projectile is suppressed, the collapsing capsule and the inert load of metal powder would work the same way and the firearm would cycle when firing no projectile. This configuration is shown in FIG. 6.

The objects of the present invention are:

-   -   1) a cartridge that can fire a light-weighted projectile of any         kind, producing an internal ballistics similar to the one of a         high mass projectile.     -   2) a blank cartridge that fires no projectile, producing an         internal ballistics similar to the one of a high mass         projectile.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of the cartridge with a generic tip-placed projectile;

FIG. 2 is a cross sectional view of the projectile traveling inside the barrel;

FIG. 3 is a cross sectional view of the moment that the projectile leaves the muzzle;

FIG. 4 is a perspective view of the cartridge with a generic tip-placed projectile;

FIG. 5 is a cross sectional view of the cartridge with a generic base-placed projectile;

FIG. 6 is a cross sectional view of the blank cartridge without projectile;

FIG. 4 is a cross sectional view of a marker projectile filled with paint.

DETAILED DESCRIPTION OF THE INVENTION

A cartridge that propels a light-weighted projectile (1) comprises a standard cartridge case (6), which contains a standard primer (7) and a load of propellant (5); a collapsing capsule which is divided in multiple parts (3); an inert load of metal powder (2); and a projectile(1).

As can be seen in FIG. 1, the cartridge of this invention comprises a collapsing capsule, which is divided in multiple parts (3). These parts (3) are assembled together in the case (6), hermetically, forming the collapsing capsule. The collapsing capsule carries inside an inert load of metal powder (2). The capsule parts (3) are radially restrained and kept assembled with interference by the cartridge case (6) before it is fired. FIG. 4 shows the cartridge assembly in a perspective view. The embodiment of FIG. 4 is the same of FIGS. 1, 2 and 3. In this embodiment, the collapsing capsule consists of two petal shaped parts (3) and a capsule base (4) which are kept together by an interference assembly with the cartridge case (6).

As can be seen in FIG. 2, when the cartridge is fired, the collapsing capsule is accelerated by the propellant gases (13), leaving the cartridge case (6). At this moment, the internal walls of the barrel (11) radially restrains the capsule parts (3), keeping the capsule assembled and hermetically closed during the internal ballistics phase of the shot. The collapsing capsule travels inside the barrel (11) with interference, like a common lead-core projectile.

As can be seen in FIG. 3, when the collapsing capsule leaves the muzzle (12), it disassembles, because there's no more radial restraints, allowing the inert load of metal powder (2) to spread in the air and the projectile (1) to fly to the target.

The inert load of metal powder (2) consists of very thin particles of a high density metal, like Tungsten. These particles decelerates very rapidly in the air and offers a low level of danger to personnel at a minimum distance of around 2 meters or wearing protective masks and clothes at closer distances.

The projectile (1) can be designed to many purposes: marker, less-lethal impact, armor piercing etc. The projectile design is not the object of the present invention. It is illustrated in FIG. 7 a projectile (1) which can be used in a marker cartridge. It consists in a capsule (8) filled with paint (9). The other embodiments show a generic light-weighted projectile (1).

In the embodiment of FIG. 1, the projectile (1) has an ogive shaped profile. In the embodiment of FIG. 5 it is shown a projectile (1) with a flat profile. In this embodiment, the projectile (1) is placed in the reward of the collapsing capsule and has a further function of obturating the propellant gases (13). In this embodiment, the projectile (1) enters the barrel (11) with interference.

The embodiment of FIG. 5 can be used as a marker cartridge, when the projectile (1) is made of a mixture of wax and ink. In this case, it's necessary to reinforce the base of the projectile with a reinforcing disc (10), which can be made of hard plastic or aluminum. The reinforcing disc (10) is fixed to the projectile (1) and both fly together to the target.

The collapsing capsule can be divided in two or more parts (3). In FIG. 1 it's show a collapsing capsule divide in two petal shaped parts (3) and a capsule base (4). FIG. 5, shows a collapsing capsule which is divided in only two petal shaped parts (3). The collapsing capsule can be fully closed by it's own parts, as show in FIG. 6, or it can be closed using the projectile (1). FIG. 1 shows the projectile (1) closing the forward portion of the collapsing capsule, and FIG. 5 shows the projectile (1) closing its reward portion.

Referring now to FIG. 6 of the drawings, the present invention can also be used as a blank cartridge, when the projectile (1) is suppressed. When the collapsing capsule is hermetically closed by own its parts (3) and carries an inert load of metal powder (2), the cartridge can cycle firearm mechanism without a projectile. In this embodiment, the cartridges propels only the capsule parts (3) and the inert load of metal powder (2). These components decelerates rapidly in the air and have no relevant effect on targets, thus this embodiment can be considered a blank cartridge. 

1. A cartridge capable of cycling a standard self-loading firearm's mechanism, said cartridge comprising: a) a cartridge case with a primer and a charge of propellant; b) a projectile, which has not enough mass itself to raise the pressure of the propellant gases to a level that the self-loading firearm cycles; c) a collapsing capsule which is divided in two or more parts that are assembled together with the projectile inside the cartridge case, is hermetic when assembled, carries an inert load of metal powder inside, is kept assembled during the internal ballistics and disassembles immediately after it leaves the firearm muzzle, detaching from the projectile; d) a load of metal powder which is packed inside the collapsing capsule, has enough mass to raise the propellant gases pressure to a level that the self-loading firearm cycles appropriately and spreads in the air immediately after the collapsing capsule disassembles.
 2. A blank cartridge capable of cycling a standard self-loading firearm's mechanism, said cartridge comprising: a) a cartridge case with a primer and a charge of propellant; b) a collapsing capsule which is divided in two or more parts that are assembled together with the projectile inside the cartridge case, is hermetic when assembled, carries an inert load of metal powder inside, is kept assembled during the internal ballistics and disassembles immediately after it leaves the firearm muzzle, detaching from the projectile; c) a load of metal powder which is packed inside the collapsing capsule, has enough mass to raise the propellant gases pressure to a level that the self-loading firearm cycles appropriately and spreads in the air immediately after the collapsing capsule disassembles.
 3. The cartridge of claim number 1, wherein said metal is tungsten.
 4. The cartridge of claim number 1, wherein said projectile is made of wax or a composition of wax and ink and is placed in the base of the collapsing capsule.
 5. The cartridge of claim number 1, wherein said projectile is a frangible capsule filled with paint.
 6. The cartridge of claim number 1, wherein said projectile is a solid body made of elastomer.
 7. The cartridge of claim number 2, wherein said metal is tungsten. 